Reciprocating mechanism



March 15, 1927.

' C. A. MCAIN RECIPROCATING IECHANISI 5 Sheets-Shut 1 Original Filed May 23. 1924 March 15, 19 27. 1,621,263

c. A. MCAIN RECIPROCATJING; MECHANISM Origifzal Filed May 2:5, 1924 5 Sheets-Sheet 2 March 15,1 A. menu RIBCIPROCATING IIBCHANISII v Qriginal Filed lay 23. 1924 5 Sheets-Shoot a INVENTO March "15. 1927.

Q A. M'GCAIN nacrraoclqms MECHANISM Original 1mm mi; 23. 1924 ,L H4 115 16 I14 5 Shula-Shep}. 4

INVENTOR.

ATTORNEY March 15,1927. c. A MCCAIN RECIPROOKTING MECHANISM Original Filed May 23. 1924 I 5 Shuts-Sheet 5 fit) Patented Mar. 15, 1927.

CYRUS A. MCCAIN, OFOAK PARK, ILLINOIS.

IR-ECIPROCA'I'ING MECHANISM.

Application filed. May 23, 1924, serial No. 715,286. Renewed August 4, 1926.

In certain classes of machines, such as printing presses ofthe reciprocating bed type, large masses have to be moved at considerable speed and then retarded, stopped and oppositely accelerated at each end of the reciprocating movement in a relatively short distance. v

In my prior Patent No. 1,063,273, granted June 3,1913, I have disclosed and claimed novel mechanism for producing such reciprocating movements in machines of the class mentioned. The present invention is an improvement of the mechanism of said patent. Although the invention is capable of use outside of the printing press art, I have chosen to illustrate the same in that connection.

The principal object of the invention is to provide novel mechanism of the class mentioned which shall be simple in constructon and yet durable and efiicient -in use and economical to manufacture. 7 f

To this end I have provided a new arrangement of gearing for driving the main reciprocating member through the mid-portions of its to and fro movements- In the preferred embodiment, aligned racks on the main reciprocating member are engaged by gear segments on intermeshing driving wheels at-the proper times to bring about the respective mid-portion drivings. I These wheels preferably make but one revolution for each cycle of operations of the reciprocating member. 7 7

Another feature of the invention resides in novel mechanism for connecting the main reciprocating member to an auxiliary member which controls the reversals of the main member. In its preferred embodiment the auxiliary member is a central pin on a link connecting the driving wheels and has a reciprocating movement approximately par allel to, andof'the'same length asthat of The various features and advantages of.

the invention will be more fully understood upon referenceto the following detailed description, taken in connection with the accompanying drawings, and the scope of the invention will be particularly pointed out in the appended claims.

In said drawings, Fig. 1' is a plan view "rorric412.5'

of a printing press having reciprocating mechanism constructed and arranged according to the present invention; Fig. 2 is a. side elevation of the same; Fig. 3 is an enlarged detail view illustrating the connection of the link with one of the associated driving wheels; Fig. 4 is a partial section of the same, the plane of section being indi- I cated by the line 44 of Fig. 3 Fig. 5 is a transverse section of a portion of the link showing the; way in wliichthe parts are lubricated. the plane of section being indicated by the line 55 of Fig. '8; Fig. 6 is an end elevation of the pressfFig. 7 is a vertical section of the link connection taken on a plane indicated. by the-line 77 of Fig. d;

Fig. 8 is a similarsection on the line 8 8 of Fig. 4; Fig. 9 is a horizontal section taken on the line 9+9 of Fig. 7; Fig. 10 is an elevation of the mechanism by which the main and auxiliary reciprocating members are connected together and freed from each other for slight independent movement; Fig.

11 is a vertical section of the same, the plane of section being indicated bythe line 11-11f of Fig. 10; Fig. 12 is a View similar to Fig. 10 but showingcertain parts in section as indicated by the line 1212 of Fig-11; Fig. 13 is a. similar view taken from the opposite side, parts being shown insection as indicated by the line 1313 of Fig. 11; Fig. 14%

is a horizontal section of the -same takenon a plaiieindicated by the line '1l14 of Fig.

13; and Figs. 15 to inclusive-are diagrammatic views illustrating different positions of the. mechanism. Throughout these views like characters refer to like parts.

Referring to the drawings in detail, 20 designates the base frame of the press. The same is preferably one casting and comprises the side members 21- and22, the end inem bers 23 and 24, a transverse centralv member 25, the corner standards 26, 27 28 and 29,

1 and the intermediatestandards 30, 31,-32

and 33. Upon the upper ends of the outer standards ust enumerated, a second frame 34 is located. This frame includes-the side members 35 and 36 and the end members. 37 and 38.. Additional frames at the feeding end of the press rest upon thejframe 34.

These are two in number and compriseiin the one nstance the horizontal member 40 and the upright 43 and in the other instance the horizontal member {11 and the ter comprises the end frames 46 and {17, but

need not be particularly deseribed herein, asthe feeder constitutes the subject matter of another application, Serial No. 723,196. filed June 30, 1924; These various frames may be secured together in any desired way. Preferably," machine screws pass through openings in flanges upon one nember into threaded engagement with tapped openings in theother membei'l These "connections are illustrated 'in'the'case of frames and '34 by the-flanges 48 and 19 "on side members and 36 respectively of the frame 34;, cooperating with machined ends of the uprights 26, 27' and'30f on the one side and {if the uprights 28, 29 and 31 on the'other side ofthe frame 20, and the same are secured together respectively by screw bolts 54' and 56. These instances will suiiice to illustrate the manner of connecting the "frames togetl'i'en and theother several connections neednot :be particularly pointed Guide ways 57 and 58 extendfrom end to end of the press between the end members 37 and 38 of the intermediate orw.ay

frame 3 1, and contain the usual slider rolls rights 65 and 66which form extensions of l the frame 34. As 'in the case'ofthe other frames, these upright-s may be secured to the "framef in any desired way. Preferably, however, connection is'made by means of "screws 67 and '68 which pass through the lower ends of the uprights into threaded engagement with tapped openings in the side members 35 and 36 of the frame i feed board 69 is'also mounted upon the uprights 43 and 4L4 of the upper fran e 39.

-As thebed '61 moves to and fro, the paper is fed fromthe'feederupon the feeder frame 15 over the feed board 69 to the cylinder 62, the impressionis made by the type upon the bed 61, and the printed sheet is delivered from the machine. The general arrangement of the machine is the same that of my prior Patent No. 1,063,273.

Motion is transmitted to the several parts of the machine through 'the main driving shaft 71 journaled at one end ina hearing formed "inthe upright 31 of the base frame r 20, and at its other end'in a bearing formed at the'upper end of a bracket frame 72 secured-i at its-base to the same upright 31.

The driving shaft 71 has a driving pulley 73 keyed to it at its outer end, and at its inner end it is provided with a pinion 74.

- direction.

ncznzes The latter meshes with. a ear wheel 7 5 of bearing formed the lateral extension 7 3 of the upright 33. The gear wheel '7 meshes with gear wheel 79 which, in turn, meshes with the gear wheel 80 upon the 1mpression cylinder 62. The gear wheel 79' is mounted on a studshaft extending inwardly from the adjacent upright 66. On the opposite'si'de of the driving shaft 71 is a shaft 81 mounted at one end 'in a bearing formed in'the uprig 1t 31, and atits other end a bearingformed in the extension 33 ofthe intermediate upright 33. The inner ends of the shafts 7 6 and 81 carry the interineshing driving wheels 84 and 85 respectively." As clearly shown, these wheels'are provided throughout gear teeth which intermesh. The wheel 84 being keyed to the shaft 76, rotates with it and, in turn, drives the wheel 85 upon the shaft 81. The wheels 84; and 85 are provided with' toothed segments 86 and 87 respec tively. The under side of the bed .61 is provided with two aligned toothed racks 88 and 88. "It will be'noted that these racks are in the plane of the segments 86 and 87. It is the teeth of these segments that engage the their peripheries with.

teeth of the racks 88' and 88, and drive the 7 bed 61 through the midportions of its reciprocating 'movements, the teeth of segment 87 always cooperating with the teeth of rack 88, and the teeth of segment 86 always" cooperatingwith the teeth of rack 88, the former to drive the bed in one direction, and the latter to drive the bed in the opposite It will also be noted that the teeth upon the wheels 84; and 85 which intermesh and are relied upon in driving wheel 8,5by wheel 84, do not come in the plane of the racks 88 and 88 and,.consequently,

do not drive the bed. I

As just noted, the segments 86 and '87 upon the driving wheels 8 1 and 85 are employed to drive the bed 61 through the central portions of its reciprocationabut as the bed approaches the endof its to. and fro movements these segments pass out of enbed consequently, further motion. of the gagement with the rack upon the bed and,

must be produced byother means. This means is provided in part by the link 89. i

which is provided with a central stud 90 which travels to and fro through a path which is approximately parallel to the path of travel of the bed 61, and which is also equal in extentv t0 the travel of the bed. hen either gear segment- 87 passes out of engagement with the rack 88, or gear 86 passes out of engagement with the rack 88, the further movement of the bed 61 is stopped and oppositely accelerated up to a speed corresponding to the peripheral speed ofthe wheels 84 and 85. WVhenthis speed is reached the proper segment 86, 011 87, is brought into mesh with its rack 88, or 88, to continue the movement of the bed at a uniform speed until the opposite end of the movement is reach-ed. When this is reached the control of the movement of the bed is again shifted to the link 89' and its stud 90 to cause retardation, stopping and opposite acceleration. In this way the gear segments 86 and 87 are alternately brought into mesh with their respective racks to drive the bed at a uniform speed, and the "retarding, stopping and accelerating at'the ends of the beds motion are accomplished by the link 89 and its stud 90. This link is provided with slots 91 and 92 through which crank pins 93 and 94 upon the wheels 84 and 85 extend. The link 89 may be held upon the pins 93 and 94 in any suitable way. However, this is preferably done by capping discs 95 and 96 secured by screws 97' and 98 screwed into the ends of the pins 95 and 94 respectively. These caps and screws which hold the link 89 in position and allow it to move freely upon the pins are bothshow'n in Fig. 2, and one set in detail in Figs. 3, 4 and 9, but omitted from the other figures of the drawing for the sake of clearness. The ends of the link 89 are provided with shoulder pieces 99 and 100 which cooperate withthe arcuate projections 101 and 102130, prevent the link'from sliding upon the pins 93 and 94 during certain positions of the parts. Pins 103 and 104 upon the link 89, and not far from the centralstud 90, co-

operate with arcuate members 105, 106 and 105, 106 for the same purpose. With the arrangement illustrated the stud 90 upon the link 89 travels in a direction approximatcly parallel to the direction of. motion of the bed 61, as before noted.

Connection is established between the stud 90 and the bed 61. so as to bring about its reversals atthe ends of its reciprocating movements by means of'a coupling member 107 which has'a vertical slot 108 at its center through which the stud 90 passes, and which near its center by any suitable means, as by means of the screws 112. The ends of the arms 109 and 110 of the yoke member 111 are connected by a crossbar 113, the same being attachedatits ends to the arms by the screws 114. The inner faces 115, 116 of the 'ment 87 upon the driving wheel 85 isatlthe point of. just beginning to drive the bed arms 109 and 110 converge upwardly. Similar faces on the member 107 are adapted to engage the inclined faces 115,116with a wedging action as the member 10! is moved upward; It will be seen that when the member 107 is moved downward, a loose connection will be formed between the stud f 90 and the bed 61, but when-the member 107 is drawn upward so that its inclined faces firmly engage the inclined faces 115,

116, the position of the stud 90 is fixed with reference to the bed61 in so far as the longitudinal movement of the same is concerned.

The stud 90 is free to pass vertically within the slot 108, but is confined by the vertical walls of the'slot-so that it cannot be moved in a direction lengthwise of the .machine.

The vertical movement, is required because of the action of the link :89 as the --,driving wheels 84 and 85 are revolved. In order to bring the coupling members 107 and-111' into firm engagement at the proper time,

the former is provided with a roller 11'? which extends into a cam track 118,- which extends lengthwise of the machine and is Thecenter of'the cam track 118 is depressed while .its ends are elevated. As the bed is reciprocated, the cam track moves the coupling member 107 downward during the secured to the central standard 32' at a point "near its center, the connection being made in any suitable way, asxb-y the screws 119.

mid-portions of the reciprocating 'movelooseconnection is done'away with and the parts are securely held together so as to prevent'the stud 90 from having any longi-' tudinal movement relative to the bed. In this way the reversal of the bed is placed directly under the control of the stud 90 upon the link 89. Obviously, as soon as the bed has been retarded,*stopped and oppositely accelerated up to the requisite speed, the cam track 118 willcause the coupling member 107 to move downward and thus again portion of the stroke.

v The movement of the bed161 through the 3 complete cycle will be readily understood from an inspection of Figs; 15 to 20qinc'lusive. In Fig. 15 the bed'61 is at the extreme left of its stroke, and the coupling members 107 and '111 are firmly seated together. bed is under, the solecontrOl of the stud- At this timefthe movement of therestore the loose connection for the. mid

90 upon the link'89, and the latter occupies;

a horizontal position. Fig. 16'illustrates,

the bed 61 in the position where the segthrough its rack 88. The left hand end of hand end downward, while the stud'90 is ment 8? upon the driving wheel 85.

mo d sho dis ce to th ti t.- he earn :roller 11'] is just entering theclown- ,wardincline of the cam track 118 to gradually-loosen the connection between the stud '90 and the bed 61. In passing to this position from the'position of Fig. 15, the pin 108 passesinto engagement with the adjacentface of the arcuate member 106, The pin 1 03 and member 106 cooperate with the member 102 and the adjacent shoulder upon the link 89 to hold the link in its proper position aunder all the strains to which it is subjected. Fig 17 illustrates the bed in its mid-position. At this time the coupling members 107 and 111 are most oo ly ehheet d an h d ing the bed is solely under the control of the {ls igr 1S advaneeef the h e v a uni r Spe 1 nues unt l t e P si on 0t s- 18 ie reee ed- In his pe it en the e men 87 uneh dr vi g Whee 8 s ins l in h ree 88am th r hs member 7 an 111 have just been brought into tight mpl es pesi a This P s the urth I movement or the bed 61 under the control This view is similar to that of Fig. 15, but shows the bed at the oppositelimit of its m ement- The bed in passing from the position of; 18 to that ofFig. 19 has been solely under the control of the stud 90 upon the link 89. V Fig. 20 illustrates the bed 61 on its. return movement at the point where it has been accelerated to the peripheral speed of the segment 86 and shows that segment just taking hold of the teeth of the rack 88". It will be apparent that upon the reverse movement the pins 103 and 104: will cooperate with the arcuate members 106 and 105 in a manner similar tothe way in whichthey cooperated with the members 106 and .105 upon the forward movement of the bed.

The speed or the bed 61 is obviously uni- ,form while it is being driven in one direc- 7 tion by tbetegment- 86 and in the other direction by the segment 87. It will also be obvious that adifi'erent retarding and accelerating motion is given to, the movement oi the stud90. upon the link 89. This move nient is similar. to that more fully described in my prior Patent No. 1,063,273, and only dilfers therefrom by reason of diil'erenees in d mensions and variations in design. 7

The cylinder 62, as before stated, is

mounted in the cylinder boxes 63 and 64., I

These cooperate with springs 121, one only of which is shown, the cranks 122 and 123, and the connectinglinks 124, in bringing about the cylinder impression in the same manner as fully disclosed in my prior Patent No. 1,225,667, granted May 8, 1917. Because of the disclosure in that patent, it does not seem necessary to further illustrate the manner in which the various parts which contribute to the cylinder impression are actuated.

As shown moreparticularly in Figs. 3, l and 9, the wheel 8% is provided with a boss 125 which is provided with a centralaperture for the reception of the pin 9%, the cen tral flange 126 on the pin 94 being: secured to the web of the wheel 84 by screws 12?. The space between the flange 126 and the capping disk 96 is occupied by the link 89 and the box 128. The latter fits over thepin 9st and has an inner circular flange having the same external diameter as the flange 126, and an outer angular portion which just fits within the slot 92 in which. it travels to and fro the machine operates. The cap 96 is firmly secured to the box 128 by screws 129, the lit of the screw 98 within the cap 96 being such that the latter may freely rotate but can not be removed in the direction of the axis or the pin. The space between the cap 96 upon the boX 128 is occupied bythe link 89. The latter has its shoulder piece 100, or 99 as the case may be, secured in place by screws 180. The upper side of the link 89 is providedwith an oiling groove v131 in which an oiling wick 150 may be laid and held in place by some such means as cotter pins 151. Suitable oil holes 132 lead the lubricant to the upper wall of the slot 92 and thence it passes to the box 128 as the latter slides to and fro in the slot. The

oil which then passes to the upper side of' the box passes over its ends and down on to the lower wall of the slot 92 and is there appliedto the under side of the box 128. The details shown in these figures are those of pin 9-1.

link and its wheel are similar.

By way of further explanation of the vertical slot 136 as the member 1,0 is raised and lowered.

The stud pin extends into an aperture and the inner flange.

It will be understood that the details of pin 93 and its connections tothe in the link 89 and at the forward side of the link has a flange 137. Screw bolts 13S pass through holes in the link into threaded engagement with tapped holes through the flange 137. In this way the pin is firmly sci cured to the link 89. 'The flange 137 is of greater diameter than the width of the slot or space 139 inthe yokeor coupling member 107 just forward of it and consequently the flange 13'? keeps the pin 90 from passing further forward and thus keeps the link 84 spaced'from the coupling members 107 and 111. The portion of the pin 90 just forward of the flange 137 is enclosed in a box 140. This box is apertured to'closely fit the ens closed portion of the pin and its vertical walls are flat and parallel and, as theparts.

move relative to each other, these flat walls ride'upon the flat faces ofthe walls of the slot 139. It will be noted too that the reduced portion of the pin 90 which engages the box 140 is of greater diameter than the width of the slot 108 in the coupling member 107. Consequently thisportion of the pin 90 cannot pass through the slot and the member 107 is accurately positioned by en gaging the adjacent shoulder on the pin while of course still being free to move relative to the pin. The forward end'of the pin v9O is reduced in diameter so that it will just.

nicely fit the slot 108 of member 107. A cap 141 is secured to the end of the pin 90 by a screw bolt 142 and the member 107 is thereby held up against the adjacent shoulder on g the pin but not so as to bind the parts but so as to leave the member107 free to move up and down relative to the pin 90.

It will be noted that the printing stroke occurs at the time the bed passes from the segment 86 and 0 and at in the case of seg ment 87 the extent not being very clearly indicated by the structure as viewed in that figure. The structure of the wheels 84 and is also indicated by breaking away a portion of the wheel 84 at the point e in Fig. 1. These wheels have central bosses which are bored out to fittheir shafts andare also'provided with peripheral bosses at the points where the pins 93 and 94 are secured as shown more particularly in Figs. 4 and '9.

Obviously many of the details herein disclosed may be varied without departing fromthe spirit and scope of the invention. Therefore, I aim to cover by the terms. of the appended claims all such alterations and modifications as rightly v come within the spirit/and scope of my invention.

. Vhat I claim as new and desire to secure by a patent of the United States. is:

v ,1. The combination of two reciprocating members movable in approximately parallel paths through equal distances, means for loosely connecting said reciprocating memhers together while said first reciprocating member is being driven at said uniform speed and operative to firmly secure said reciprocating members against relativelongitudinal movement as said members approach the ends of their to and fro movements to place the retardation, stoppage and acceleration of the first reciprocating'memher up to said uniform speed under the control of the second reciprocating member.

2. The combination of two reciprocating members movable in. approximately parallel paths through equal distances, means for driving the first, reciprocating member through the mid-portions of its to and f ro movements, at a uniform speed, a coupling member rigidly fixed to one of said reciprocating members and extending into proximity to the" other at all times, a second I ing said second coupling member into and out of holding position withsaid first coupling member as said reciprocating members pass respectively into and out of the end portions of their to and fro movements.

3. The combination of twoi'recip'rocating members movable in approximately parallel paths through equal distances, means for driving the first reciprocating member through the mid-portions of its to and fro movements at a uniform speed, a yoke rigid ly connected to one of said members and'at all times embracing the other, a member for centering said second reciprocating member within said yoke, and a cam for shifting said centering member to centering position as said reciprocating members approachthe ends of their'reciprocating' movements.

4.'The combination of a reciprocating member having two racks, intermeshing gear wheels rotatable about fixed axes, each said wheelhaving a segment for engaging one of said racks to drive said reciprocating member through themid portion of its move ment, one wheel inone direction and. the other in the opposite'direotion, a stud, means actuated, by said gear wheels to drive said stud to and 'fro in'a path approximately parallel to and-coextensive with that of said reciprocating member, and means loosely connecting said reciprocating member. to

member and stud against relative longitu-f .dinal movement as said reciprocatingmember' andstud approach the ends of their 7 reciprocations to place the retardation, stopthe'other'in'the opposite direction, a stud,

means" aotiiatedby saidgear' Wheels to drive said stud to and fro in a path approximately parallel to and coextensive with that of said reciprocating member, a coupling member rigidly seoiired to said reciprocatin member and extending into proximity to said stud at all tinie e second couplin'gmember cooj' erating with said first coupling member to firmly hold said stud and" reciprocating member together against relative longitudinal move'inent,'and'means for moving said second couplingmember into" and out of holding, position with said first coupling member assaid reciprocating member and stud-pass respectively intoa'nd'out 0ithe end portions of their'to and fro movements.

'GL The combination of a reciprocating member having two racks, intermeshing gear Wheels rotatable about fixed axes, each said Wheel having a segment for engaging one of said racks. to drive said reciprocating Imember through the mid portion of its movement, one wheel in one direction and the other Wheel in the opposite direction, a stud, means actuated by said'gear' wheels to drive said stud to and fro in a path approximately parallel to and coextensive with that of said reciprocating member, a yoke rigidlyconnected to said reciprocating member and at all times embracing said stud,-a member for centering said stud Within'said yoke, and a'cam for shifting said centering member to centering position as said reciprocating member and stud approach the ends of their reciprocating movements.

71 The combination of 'a-driv'en reciproeating member, a driving reciprocating meniber movable in a path approximately parallel to the path of travel of said dilvn member, means connecting said members at all times, loosely during the mid portions of their reciprocations, and tightly, as to relative longitudinal n'iovement, during the end portions of their reciprocations, and means for giving said driven member a movement (imag ne 1111a portions er its 7 ciproeauonsdies-em 'from that of said d1 viii-g. member during" the same mid portio'ii's i W 7 y 7 Thecomtinari were drivenreciprdeating; meiiilifi, driving, reciprocating fi1aiber -iii6va151e-in"a path ap'prdzmrrafeiy parallel to that of said driven member, a coupling member ri'gidly'fixed to one of said reciprocating members and extending into proximity to the other at all tines, a second coupling member cooperating with said first coupling member to firmly hold said reciprocating members together against relative longitudinal movement, meanstor moving said second coupling member into and out of holding position With said first coupling member as said reciprocating members pass r'espectivelyinto and out of the end portions of their reciprocations, and means for giving said driven member a movement during the mid portions of'its reciprocations differenttrom' that of said driving member during the same mid portions. 1 7' 9. The c'on'ibinat'ion of a driven recipro eating member, a driving reciprocating member movable in a path approxi ate-1y parallel to that of said driven member, a yoke rigidly connected to one or saidme'mbers and at all times embracing the other, a

a member for centering said other'rec'ip'roeating member Within said yoke, a c'a'm'for shitting said centering member to centering position as said reciprocating member's approach the ends of their reciprocating'move-- ments, and means for giving said drivenmember' a movement during" the mid por tions of its reciprocations different from that of said driving member during the same mid portions. v

10.'The' combination of a reciprocating member, a stud, two oppositely driven Wheels, means actuated by said Wheels to drive said stud to and fro in a path approximately parallel to that of said recipr'o eating member, means connecting said reciprocating member and stud togethera't all times, loosely during the mid portions of theirreciprocations and tightly, as to rem tlve longitudinal movement, during the end portions of their re'ciprocations, and means for giving said reciprocating member a movement during the mid portions of its reciprocations different from that of said stud during the same mid portions.

11. The" combination of a reciprocating member, a stud, two oppositely driven wheels. means actuated by said wheelsto (i ive said stud to and fro in a path approximately parallel to that of said reci o'rocating member,'a coupling member rigidly fixed to said reciprocating ni'einbe'r and extendi into proximity to said stud at' all times, a second coupling member cooperating with said first coupling member to firmly'liold emit-emprocating. member and studtogetliena inst 's for relative longitudinal movem nt, mean mov ng sa1d second coupling member'fi to and out or Holding pesitionfvvi'th said fir t coupling member said reoiprocatin mbe and stud pass respeetive1y-inwand out ion of the end portions of their reciprocations, and means for giving said reciprocating member a movement during mid portions of its reciprocations different from that of said stud during the same mid portions.

12. The combination of a reciprocating member, a stud, two oppositely driven wheels, means actuated by said wheels to drive said stud to and fro in a path approximately parallel to that of said reciprocating member, a yoke rigidly connected to said reciprocating member and at all times embracing said stud, a member for centering said stud within said yoke, a cam tor shifting said centering member to centering position as said reciprocating member and stud approach the ends of their reciprocations, and means for giving said reciprocating member a movement during mid portions of its reciprocations different from that of said stud during the same mid portions.

13. The combination of a pair of oppositely rotating intermeshing gear wheels, crank pins on said wheels, a link having slotted connection with said pins and positioned so as to extend past the point of engagement between said wheels in all positions of the parts, a stud at the center of said link, a reciprocating member having a longitudinal travel equal to that of said stud, and coupling means for operatively connecting said stud to said reciprocating member.

14. The combination of a pair of oppositely rotatable intermeshing gear wheels, crank pins on said wheels, a link having slotted connection with said pins and positioned so as to extend past the'point of engagement of said wheels in all positions of the parts, shoulder pieces at the ends of the link and arcuate projections on said wheels cooperating to prevent sliding of said link upon said pins in certain positions of the parts, pins upon said link on opposite sides of its center and a pair of arcuate members on each of said wheels extending from near the wheels center to near its periphery and likewise cooperating to prevent sliding of the link under unusual circumstances, a reciprocating member, and coupling means for uniting said reciprocating member to said link to give the latter control over the movements of the'former. .15. The combination of a pair of oppositely rotating intermeshing gear wheels, crank pins on said wheels, a link having slotted connection with said pins and positioned to pass the point of engagement between said wheels in all portions of the parts, a stud at the center of said link, a reciprocating member, and a connection between said reciprocating member and stu in all positions of the parts.

16. The combination with a printing press frame, of a reciprocating bed at the usual height, centrally disposed racks on the under side of said bed near its transverse center, two shafts journaled in said frame, intermeshing gear wheels on said shafts ex tending almost the aforesaid height, a toothed segment on one quarter'ofthe'pe' riphery of each of said wheels in addition to the intermeshing teeth, said segments operating to engage said racks respectively to drive said bed during mid portions of its to and fro movements, crank pins on said wheels, a link having slotted connection at its ends with said pins, coupling members always connecting said bed to the center of said link, loosely when said segments are in mesh with said racks and at other times tightly as to relative longitudinal movement, and a cam on said frame beneath said bed operative to shift said coupling members to establish said loose and tight connections.

In witness whereof, I hereunto subscribe my name this 21st day of May, 1924:.

CYRUS A. MCCAIN. 

